Police in Mexico have conducted their biggest crackdown on illegal logging with raids on 19 clandestine sawmills in which 56 mill workers, lumberjacks and truck drivers were arrested.

The raids also netted 600 truckloads of timber, much of which was plundered from the Monarch butterfly nature reserve, which has been devastated in recent years.

Authorities said the seizures represented 210,000ft³ of logs and boards or about 1,750 adult trees.